The Galloway School, Atlanta Girls’ School, The Westminster Schools and North Atlanta High School were among the schools participating in the latest walkout to call for gun control measures.

The National School Walkout was held at schools across the country at 10 a.m. on April 20, the 19th anniversary of the mass shooting at Columbine High School.

It is the latest in a series of protests held in the wake of school shooting in Parkland, Fla. that killed 17 people, including a nationwide school walkout and march. Several local schools participated in the previous walkout, which were student-led.

About 200 Westminster students participated in the walkout, said Justin Abraham, a spokesperson for the West Paces Ferry private school. A 17-minute moment of silence was held, followed by four student speakers, Abraham said.

About 300 students at North Atlanta High participated, said Seth Coleman, an Atlanta Public Schools spokesperson. The students held a 30-minute protest on the football field, Coleman said.